There are a few surprises in store for the Harpers, as the family sitcom returns for a new series.

Just as Ben and Susan are leaving for a dinner with their friends, the Mortons, a mystery man arrives at the house, asking for Janey. It turns out to be someone her parents were beginning to think didn’t actually exist: Kenzo’s father, Mark.

After much deliberation, Janey decides to grant Mark access to Kenzo, but she soon regrets her decision when he fails to bring his son home on time. Things go from bad to worse when Janey learns that Mark has been married for two years and that Kenzo has already met his “new mummy”.

In an evening full of surprises, Ben and Susan finally make it out for dinner, where the Mortons reveal that they are having trouble conceiving and make an unexpected request: for some of Ben’s sperm! Delighted, Ben spends the rest of the evening revelling in his own fertility – but his glee is short-lived when he visits the sperm clinic…

Good Friday 6 April
8.30-9.00pm BBC ONE